高考英語語法考點講練：情態(tài)動詞和虛擬語氣

1、精品文檔（2011高考英語語法考點講練：情態(tài)動詞和虛擬語氣導(dǎo)讀 “2011高考英語語法考點講練：情態(tài)動詞和虛擬語氣”供廣大考生備考使用?！究键c分析】情態(tài)動詞1.考查情態(tài)動詞的基本用法shall用于一、三人稱疑問句表示征求對方意見;用于二、三人稱陳述句表示說話人給對方的命令、警告、允諾或威脅等;may表示“允許、可以”，語氣比較委婉。must用于疑問句，表示責(zé)備、抱怨的感情色彩，意思為“偏偏，偏要”，mustnt表示禁止，是說話人強有力的勸告。cannot 表示“不可能”;need not 表示“不必要”;may not 表示“可能不，可以不”。neednt表示“沒有必要”would表示過去反復(fù)

2、發(fā)生的動作或某種傾向表示經(jīng)過努力而成功的某一次動作，只能用was/were able to,而不能用could;could還可以表示過去的某種能力考查情態(tài)動詞用作答語的情況2.考查情態(tài)動詞+動詞不定式一般式表推測的用法肯定的推測一般用must,should,may(might)或could(不用can)，其中，must的語氣最強，譯為“肯定”、should的語氣次之，譯為“很可能”、“應(yīng)該”;按常理推測的may(might),could語氣最弱，譯為“也許”。否定的推測：語氣不很肯定時，常用may not,might not或could not，譯為“可能不”“也許不”;否定語氣較強時，則用c

3、ant，譯為“根本不可能”、“想必不會”，表示驚異、懷疑的感情色彩疑問句中推測往往用can或could3.考查情態(tài)動詞+動詞不定式的完成式表推測的用法4.考查情態(tài)動詞+動詞不定式完成式的其他用法should(ought to)+不定式的完成式：本來應(yīng)該做而實際上又沒有做。其否定形式表示某中行為不該發(fā)生卻發(fā)生了。neednt+不定式的完成式：本來不必要做的而實際上又做了could+不定式的完成式：本可以做而實際上未能做,含有遺憾的意味虛擬語氣1.虛擬條件句的基本結(jié)構(gòu)及其用法與現(xiàn)在事實相反的虛擬條件句與過去事實相反的虛擬條件句與將來事實相反的虛擬條件句2.虛擬語氣的活用時間錯綜虛擬結(jié)構(gòu)省略if的虛

4、擬結(jié)構(gòu)并列連詞或副詞暗示的虛擬結(jié)構(gòu)介詞或介詞短語暗示的虛擬結(jié)構(gòu)as if / as though方式狀語從句中的虛擬語氣名詞性從句中的虛擬語氣分詞短語暗示的虛擬結(jié)構(gòu)上下文語境中的虛擬結(jié)構(gòu)【知識點歸納】i.情態(tài)動詞1.表示“能力、許可”的can /may表示能力的情態(tài)動詞用can/coulda computer_think for itself, it must be told what to do.a.cant b.couldnt c.may not d.might not表示許可時用may/might ,can/could 都可以，但在問句中用could?或might? 以使口氣委婉客氣，其

5、回答一定要用can或may，以使回答口氣明確(must表示一定，必須，mustnt表示禁止，不許可)could i call you by your first name? yes, you_a.will b.could c.may d.mightjohnny, you_play with the knife, you_hurt yourself.a. wont/cant b.mustnt/may c.shouldnt/must d.cant/shouldnt在肯定句中could不可以用來表示過去某一特定場合的能力，而要用was/were able to。如不可以說：they could ju

6、mp into the sea before the boat was blown up而要說：they were able to/managed to jump intothe fire spread through the hotel very quickly but everyone_get out.a.had to b.would c.could d.was able to但在否定句中could/was(were)able to可以通用:i couldnt/wasnt able to see him yeaterday.表示許可時用may/can都可以。只不過用may時較側(cè)重講話人的許

7、可，而can較側(cè)重客觀情況的許可，must則表示必須做某事。2.表示“推斷、判斷”的can,may,must在肯定句中都可以用來表示可能。在含義上must語氣最為肯定,may表示的是事實上的可能性：peter_come with us tonight, but he isnt very sure yet.a.must b.may c.can d.will而can表示的是邏輯上的可能性：mary is in poor health. she can be ill at any times.在否定句中只能用can和may。此時cant用以代替mustnt，語氣比may not更強。cant中文可以

8、翻譯為“不可能”、may not中文可以翻譯為“可能不”。michael_be a policeman, for hes much too short.a.neednt b.cant c.should d.may在疑問句只能用can，不能用may和musthe may be very busy now.can he be very busy now?he must be very busy now.can he be very busy now?3.表示“請求、提議”(用在疑問句中)的can和could，這時could比can語氣更婉轉(zhuǎn)can(could)you give me a lift

9、to the station?你(您)能不能讓我搭你(您)的車去車站呀?4.表示“驚訝、懷疑”(用在疑問句中)的can和could，這時could比can語氣更婉轉(zhuǎn)who can it be at this time of day?這個時候到底會是誰呢?5.構(gòu)成下列特殊句式的cancan not/can nevertoo cannotenough“無論怎么也不為過分，越越好，非?！眘ince it is a good thing,we cannot do it too soon.既然是好事情，我們越早開始做越好。cant help doing,cannot help but do,cannot

10、 but do“禁不住，不由得，不得不”i cannot help admiring the picture whenever i look at it.每當(dāng)我看到這幅畫時，我都禁不住要鑒賞它。when a close friend dies,you cannot but feel sad.親密的朋友去世時，你會不由得感到悲傷。6.表示祝愿、祝福的may,此時句子用倒裝語序may he live to an old age!愿他長命百歲!may god be with you!愿上帝保佑你!7.shall/should用于人稱意義shall第一、三人稱征求對方的意見第二、三人稱說話人給對方的警

11、告、命令、允諾、威脅用于法律、法規(guī)等條文中應(yīng)，須，得what shall we do this evening?注意：may用于征求對方的許可，而shall用于征求對方的意見或指示：may i have a look?我能看一看嗎?shall i have a look?需要我看一看嗎?you shall fail if you dont work harder. (警告)he shall have the book when i finish reading. (允諾)he shall be punished.(威脅)the fine shall be given in cash.罰款須以現(xiàn)

12、金繳納。should 意義（表義務(wù)、責(zé)任的）應(yīng)該（表預(yù)期的）應(yīng)該會，想必會，一定會把（表驚訝、遺憾的）竟然、居然（與疑問詞連用，表意外、驚訝、納悶等的）究竟是，到底（用于表示命令、建議、請求等詞后面的that從句中，且should可以省略）應(yīng)該，必須you should apologize to him.the photos should be ready by 12:00.im surprised that you should speak in such a way.who should ccome in but my old friend betty.我當(dāng)究竟是誰進來了呢，原來是我的老朋

13、友貝蒂呀。i suggested that he (should)change his mind.my suggestion was that he (should)change his mind.注意：ought to表示 “應(yīng)該” (與should同義, 只是語氣稍重一些), 也可表示推測。you ought to take care of him.he ought to be home by now.8.will/would請求、建議，would比will委婉客氣would you pass me the book?表示意志、愿望和決心i will never do that again

14、.they asked us if we would do that again可表示過去反復(fù)發(fā)生的動作或某種傾向during the vacation he would visit me every weekthe wound would not heal.表示估計或猜想it would be about ten when he left home.what would she be doing there?9.dare和needneed作為情態(tài)動詞只有一種形式，只用于否定句和疑問句。dare作為情態(tài)動詞用時有兩中形式：dare和dared兩個詞形。除了可以用于否定句和疑問句外，還可以用于條

15、件從句或表示懷疑的句子中。if he dare come,i will kick him out.i dont know whether he dare say.note:he doesnt dare(to)answer the question.does she dare(to)enter the dark room?10.情態(tài)動詞+have done的用法could+have done：本可以做而實際上未能做you could have done better, but you didnt try your best.cannot+have done：表示對過去行為的否定推測he cann

16、ot have been to that town.can+主語+have done：表示對過去行為的懷疑或不肯定can he have got the book?might(may)+ have done：對過去發(fā)生的行為不太肯定的推測he may not have finished the work.if we had taken the other road, we might have arrived earlier.(mood:might>may,possibility:mightmust+have done：對過去發(fā)生的行為肯定的推測。其否定式為：cannot have do

17、neyou must have seen the film.you cannot have seen the film.neednt+have done：本來不必要做的而實際上又做了you neednt have watered the flowers,for it is going to rain.注意：didnt need to(have to)do :沒有必要做而實際上也沒有做i didnt need to clean the windows.my sister did it 2 hours ago.should(ought to)+ have done：本來應(yīng)該做而實際上又沒有做。其否

18、定形式表示某種行為不該發(fā)生卻發(fā)生了。you should have started earlier, but you didnt.she shouldnt have taken away my measuring tape, for i wanted to use it.注意：本結(jié)構(gòu)還可以表“推測”的意思he should have finished the work by now.到現(xiàn)在他應(yīng)該已經(jīng)做完那項工作了。11.其它情態(tài)動詞have tohave to表示 “必須, 不得不”, 在這個意義上與must很接近, 但must表示的是說話人的主觀看法, 而have to表示的卻是客觀需要.

19、have to比must有更多的形式。the tv set is broken. i have to buy a new one.the students will have to know how to use the computers.注意：在回答must的問句時, 否定式常用need not(neednt)或dont have to表示 “不必”。而不用must not, 因為must not表示 “不可以”。used to表示過去的習(xí)慣動作或狀態(tài)(現(xiàn)在已不復(fù)如此)did you use to go there to see your brother? /used you to go

20、there to see your brother?yes, i did(used to). /no , i didnt (usednt).注意：would也可表示過去反復(fù)發(fā)生的動作或某種傾向，但是不涉及到現(xiàn)在。had better表示 “最好(做)”we had better go now.其否定式為had better notii.虛擬語氣(一)一般虛擬結(jié)構(gòu)類別用法例句if引導(dǎo)的條件從句與現(xiàn)在事實相反從句動詞：過去式（be用were）主句動詞：should/would/could/might+動詞原形if he were here, he would help us.與過去事實相反從句動詞

21、：had+過去分詞主句動詞：should/would/could/might+have+過去分詞if i had been free, i would have visited you.與將來事實相反從句動詞：過去式 / should+動詞原形 / were+不定式主句動詞：should/would/could/might+動詞原形if it should rain tomorrow, we would not go camping.注意:主句中的should只用于i、we，但在美國英語中，should常被would代替;從句中的should可用于各種人稱，且不可以被would所代替。(二)混

22、合虛擬結(jié)構(gòu)1.不同時間的虛擬if he had listened to me, he would not be in trouble now.(從句與過去事實相反，主句與現(xiàn)在事實相反)if he had told me yesterday, i should know what to do now. (從句與過去事實相反，主句與現(xiàn)在事實相反)if i were you, i would have gone to her birthday party. (從句與現(xiàn)在事實相反，主句與過去事實相反)if you hadnt lent me some money, i couldnt have bou

23、ght the new house and most likely i would be still living in the dangerous house now. (從句與過去事實相反，and后面的主句與現(xiàn)在事實相反)2.虛擬與陳述的混合he could have passed the exam, but he wasnt careful enough.you should have come earlier. the bus left a moment ago.(三)特殊句式虛擬結(jié)構(gòu)1.省略連詞if。在書面語中，如果虛擬條件從句中有were，had 或 should，可以把if省略，

24、把這幾個詞放到主語之前，構(gòu)成主謂倒裝。should he come (if he should come), tell him to ring me up. 他要是來了，讓他給我打個電話。were i you (if i were you), i would not do it. 我要是你，就不做這事。2.suggest, order, propose, request, require, demand, advise, insist+ 賓語從句(should )dohe suggested that we (should) save money for the future.the unde

25、rgraduate insisted that he (should) go to work in the south.注意：當(dāng)suggest表示暗示，insist表示堅持觀點,事實時，后接的賓語從句應(yīng)當(dāng)用真實語氣。his silence suggested that he agreed with my decision.he insists that doing morning exercises does good to peoples health.3.it is suggested/advised/ordered/requested/required+ that從句(should) d

26、oit is proposed that more students should go to university.4.my advice/suggestion/request/requirement/order/proposal+ is +表語從句(should)domy advice is that you should practise speaking english as often as possible.the order from the commander was that the troops should set off for the front immediatel

27、y.5.his suggestion/advice/request/requirement+ 同位語從句(should )do+ is.the request that they should get more is reasonable.6.it is natural/necessary/strange +that從句 (should) do表驚奇、懷疑、惋惜、不滿、理應(yīng)如此等。its strange that he should have missed the train. (表竟然)it is important that we should learn from others.(表理應(yīng)

28、如此)it is a pity that he should not go with us.(表驚訝、不滿)7.wish + that clause (did/were 與現(xiàn)在相反)wish + that clause (would/could/might + do與將來相反)wish + that clause ( had done 與過去相反)i wish i could go with them tomorrow.i wish i had never met him.8.it is (high/about) time + 從句(did或should do )it is (high/abo

29、ut) time we went home.9.would rather + clause (did 與現(xiàn)在或?qū)硐喾?;(had done 與過去相反)i would rather you came tomorrow.i would rather you hadnt told her the news.10.省去條件從句或主句：表示虛擬語氣的主句或從句有時可以省略，但其含義仍可以推知。省去條件從句you could have washed your clothes yourself. 你本可以自已洗衣服的。省去了"if you had wanted to")(事實是:你自

30、己沒洗衣服，因為你不想洗。)省去主句(常用以表示愿望) if only + clause ( did/were與現(xiàn)在相反)/ (would/could/might + do與將來相反) /( had done 與過去相反) “要是.就好了“if my grandmother were with me! 如果我的祖母與我在一起多好啊!(事實是:祖母已不在世。)if only she had not left! 如果她沒走就好了!(事實是:她已經(jīng)走了。)if only he would come tomorrow!if only i had taken her advice!if only i were ten years younger!注意：only if是“只要”的意思，從句中用陳述語氣。11.as if + clause (did/were 與現(xiàn)在相反) / (would/could/might + do與將來相反)/( had done 與過去相反)she